Any decent kydex holster will work for most competitions.
For Steel matches just loosen up the tension a little bit and for rough and tumble stuff give the screws a little twist.
I am using these holsters. Flip the lever and it aint coming out. And he does pretty colors if you are into that kind of thing.
https://gxproductsusa.com/gx-vice-holster/
Any inner/outer belt combo works fine as long as the outer belt is stiff.